Oval compasses.



G. SGHREIBER.

OVAL GOMPASSES. APPLICATION FILED JULY 21, 1906.

3 lllll v uunnmlnm llggl 5/ UNITED STATES PATENT OFFICE.

CARL SCI-IREIBER, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO JOHN BITZER, OF CHICAGO, ILLINOIS.

OVAL COMPASSES.

Specification of Letters Patent.

Patented March 5, 1907.

Application filed July 21,1906. Serial No. 327,192.

1'0 all whom, it may concern:

Be it known that I, CARL SCI-IREIBER, a subject of the Emperor of Germany, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Oval Compasses, of which the following is a specifica- E theremto a pin 8, with a sharp point, and

tion. I

1 It is exceedingly, diflicult with ordinary compasses to make a perfect oval or ellipse, owing to the fact that the centers must be shifted a number of times inorder to obtain the major and minor axes of the oval or elliptical figure.

The objects of the present invention are to construct an instrument in the form of a compass by means of which the correct and proper adjustment can be readily and quickly made for producing or inscribing oval or elliptical figures of different dimensions, to enable a continuous line to be produced by the action of the pen which will be more satisfactory than the usual broken lines obtained by the use of ordinary bow or circular compasses, to enable the focal points for the major and minor axes 'to be quickly adjusted without the requirement of any special skill and labor and when adjusted have the focal points in correct relation one to the other, and to improve generally the construction and arrangement of the parts entering into the formation of the oval compass as a whole.

The invention consists in the features of construction and combination of parts hereinafter described and claimed as new.

In the drawings, Figure 1 is a sectional elevation of the oval compass of the invention; Fig. 2, a front elevation of the parts shown in Fig. 1; Fig. 3, a rear elevation of the base or frame with the ruling-pen swung to one side, and Fig. 4 a top or plan view.

The oval compass of the present invention is constructed with a base or frame 1 in the shape of an annular band, preferably of metal, extending up from which is a strip or plate 2, from which on each side project guides or ears 3 on a curve coinciding with the curve of the base or frame, and between the guides or ears 3 and the base or frame 1 on each side of the center plate or strip 2 is a slot 4 for the passage of the arm or bar carrying the ruling-pen. The base 1, center strip 2, and guides or cars 3 in the construction shown are formed integral and constitute a base-support, and to the outer rear face of these parts is attached a post or standard 5, terminating in a finger-piece or handle 6, by means of which the instrument can be set in position for use. Each opposite side of the base or frame 1 has secured thereto lugs or cars 7, and each lug or ear 7 has entered each pin is locked in adjusted position by thumb-screw 9 or other suitable means, so that the points of the pins project sufficiently below the bottom edge of the base-support to enter the paper and hold the instrument in position for use. The pins 8 are opposite each other, but are arranged so as to be on opposite sides of a center line passing through the trackway for the upper focal point, as shown in Fig. 4.

A pair of rods 10 extends fore and aft across the base or frame 1, with a space between the two rods, which space forms a trackway or guideway for one of the sliding axes, which may for convenience be termed focal points. A pair of rods 11 extends across the guides or ears 3, and the two rods 11 form in the space between them a track way or guideway for the upper focal point. The upper and lower guideways stand in right-angle relation to each other, but are set inclined in relation to the center lines of the base or frame, as shown in Fig. 4.

A Wheel 12, having a grooved periphery, is located and travels between the lower bars 10 in the guideway or trackway between the bars, and this wheel is loosely mounted on a pin or pintle 13, depending from a head 14 on the inner end of the swinging arm or bar 15, carrying the ruling-pen, and, as shown, the wheel is held on the pin or pintle between the head 14 and a washer or nut 16 on the end of the in or pintle, so that the wheel is free to revo ve on the pin or pintle and travel back and forth in the guideway or trackway between the rods 10 as the focal points change in the movement of the ruling-pen.

A wheel 17, having a grooved periphery, is located and moves in the guideway or trackway between the upper rod 1 1 and forms the other focal point of the instrument, and this wheel is loosely mounted on the stem of a set or thumb screw 18, the threaded end of which enters a slide or socket 19 on the arm or bar 15 and locks the arm or bar in the adjusted position for the focal points fur- IOC nished by the wheels 12 and 17 and enables the wheel 12 to be adjusted nearer to or farther from' the wheel 17, as required for the oval or ellipse to be made. The nearer the two focal points approach each other the more circular will be the figure produced.

A slide or socket 20 is located and movable on the arm or bar 15 and is locked in an adjusted position on the arm or bar by a set or thumb screw 21, the threaded end of which extends into the socket for the end to engage the arm or bar. A post or stand ard 22 extends out from the slide or socket 21 and at its upper end has a head or socket 23, through which the stem 24 of the ruling-pen can slide, and the ruling-pen can be of the ordinary construction, with the pensection 25 pivoted to the stem-section 241, as usual. The stem-section has a finger-piece or handle 26 and is locked in an adjusted position in the head or socket 23 by a set or thumb screw 27, entering the head or socket for its end to engage the stem of the pen.

The two wheels 12 and 17 serve as focal points, and their operative position with respect to each other can be adjusted as may be required for inscribing or making ovals or elliptical figures of different radii from the major and minor axes, and in adjusting the focal points the set or thumb screw 18 is loosened and the arm or bar 15 moved toward or from the slide or socket 19, as may be required for the adjustment of the focal points, and when adjusted the focal points coact for enabling the ruling-pen to make the line of the desired oval or ellipse. The pen is moved in or out on the arm or bar 15 by re leasing the set or thumb screw 21 and mov ing the slide or socket 20, and when the desired position for the pen is reached the pen is locked in position by engaging the set pr thumb screw 21 with the face of the arm or )ar.

In use for making an oval or ellipse the difference between the major and minor axes is to be first ascertained. The arm or bar 15 is then moved in or out and adjusted at the proper point for the difference between the two focal points furnished by the wheels 12 and 17 to equal the difference between the major and minor axes of the desired figure, and when the proper adjustment is reached the swinging arm or bar 15 is locked against end movement by engaging the end of the set or thumb screw 18 with the face of the bar. The base or frame 1 is fixedly held in position by entering the pin-points 8 into the paper or board, so that the base or frame is held against rotation. The ruling-pen is then adjusted on the arm or bar 15 so that its tip will be located a distance from the line of the pin-points of the base or frame equal to the minor axis of the desired oval or elliptical figure.

locked in the adjusted position by the thumb or set screw 21 engaging the face of the swinging arm or bar the pen can be swung, by means of the handle or finger-piece 26, carrying with it the swinging arm or bar and describing a true oval or ellipse. The swinging of the arm or bar 15 will cause the focal wheels to travel in their trackways or guide ways, so as to form a resulting line drawn by the pen, which line will be in the form of the intended oval. The upper focal wheel or point moves in the trackway or guideway between the rods 11, and the lower focal wheel or point moves in the lower guideway or trackway between the rods 10, and the move ment is one that will permit the necessary reciprocation of the parts caused by the adjustment of the focal Wheels, which reciprocation, in combination with the circular travel of the ruling-pen, will result in the forming or producing of a true oval or elliptical figure having a minor axis equal in length to the distance between the axis of the focal wheel 17 and the pen-point and having a major axis equal to the length of the minor axis plus the distance from the centers or axes of the pintles carrying the focal wheel or the entire distance from the pen-point to the axis of the wheel 12.

It will be seen that by means of the compass of the present invention an instrument of simple form is obtained and which is well adapted to meet the requirements of the draftsman in use; that can be easily and quickly adjusted; that is simple and easy of operation; that is of small and compact size, and which can be manipulated by persons unskilled in the use of mechanical-drawing instruments. The use of the instrument will result in the production of lines which will be more accurate than lines produced by ordinary compasses, and the adjustment of the focal points and the pen to obtain the correct minor and major axes for the figure to be produced can be quickly made. The compass is intended for use and can be used with a pen, pencil, or other line-inscribing instrument.

What I claim as new, and desire to secure by Letters Patent, is

1. An oval compass consisting of a slotted base or support, an upper and a lower set of focal guide-rods extending in transverse relation to one another, a laterally-extending arm adapted to swing between the guide-rods and provided with a sliding focal connection for each of the guide-rods, and an inscribing instrument carried by the swinging arm, sub stantially as described.

2. An oval compass consisting of a slotted base or support, an upper focal guideway ex tending across the support above the slot therein, a lower focal guideway extending After the focal points and the across the support below the slot therein and pen have been properly adjusted and the pen 1 in transverse relation to the upper guideway,

an arm adapted to swing within the slot in the base-support and between the upper and lower focal guideways, sliding focal connections between the swinging arm and each of the guideways, and an inscribing instrument carried by the arm, substantially as described;

3. An oval compass consisting of a slotted base-support with pins for holding it stationary, an upper focal guideway consisting of parallel rods extending across the support above the slot therein, a lower focal guideway consisting of parallel rods extending across the support below the slot therein, an arm adapted to swing within the slot in the base, a pair of focal wheels pivoted to the arm and adapted to travel between the rods forming the upper and lower focal guideways, and an inscribing instrument carried by the arm, substantially as described.

4. An oval compass consisting of a slotted base-support with pins for holding it stationary, an upper focal guideway consisting of parallel rods extending across the support above the slot therein, a lower focal guideway consisting of parallel rods extending across the support below the slot therein, an arm adapted to swing within the slot in the base, a pair of focal wheels pivoted to the arm, one of the wheels being adjustable upon the arm, and adapted to travel between the rods forming the upper and lower focal guideways, and an inscribing instrument carried by the arm, substantially as described.

5. An oval compass consisting of a circular base slotted around a portion of its periphery, an upper focal guideway extending transversely of the base above the slot, a lower focal guideway at right angles to the upper guideway and extending transversely of the base below the slot, an arm adapted to swing within the slot and having at its inner end a focal wheel pivoted in fixed position and adapted to travel within the lower guideway, a socket slidably and adjustably mounted on the swinging arm, an upper focal wheel pivoted to the socket and movable within the upper focal guide-way, and an inscribing instrument carried by the arm, substantially as described.

CARL SOHREIBER.

Witnesses:

'OSCAR W. BOND,

O. F. 000x131. 

